Machine for straightening pipe



C. W. M CLURE ETAL MACHINE FOR STRAIGHTENING PIPE May 1, 1951 2 Sheets-Sheet 1 Filed June 25, 1948 m Mm 0 0 m% W e M AW fix 3 W? W @MA Patented May 1, 1951 UNITED sTATEs PATENT OFFICE MACHINE FOR STRAIGHTENINPIPE Carroll W. McClure, McKeesport, and Samuel Webb, Pleasant Hills, Pa., assignors to National Tube Company, a corporation of New Jersey Application June 25, 1948, Serial No.- 35,096-

" 2 Claims.

This invention relates to machines for straightening pipe during its manufacture.

As a step in the manufacture of steel pipe, the pipe is subjected to a straightening operation, commonly either with a rotary straightening machine or a gag press. Rotary machines with which we are familiar straighten the pipe by bending it through a series of reverse bends. Such action has the disadvantage that the entire pipe is cold-worked, which may be undesirable. Gag presses engage the pipe at spaced points and remove the bends by proper application of lateral thrusts. Gag presses thus overcome the disadvantage of rotary machines, but those with which we are familiar are undesirably slow.

An object of the present invention is to provide improved pipe straightening machines that shaft rotates countergclockwiseas viewed in Fig,

avoid any extensive cold-working pipeand yet aretcapable of rapid and continuous operation. A further object of the invention is to provide improved pipe straightening machines that operate rapidly and continuously and yet straightenby application of lateral thrusts according to the principle of gag presses.

A further object of the invention is to provide improved machines for straightening pipe wherein pipe lengths are straightened by being bent to the elastic limit or beyond while rotating with-r out being appreciably cold-worked.

In accomplishing these and other objects of the present invention, we have provided improved details of structure, preferred forms of which are shown in the accompanying drawings, in which:

Figure 1 is a proved. pipe straightening machine embodying features of the present invention;

Figure 2 is an end elevational view of the machine shown in Figure 1;

Figure 3 is atopplan view of 'a modified form of pipe straightening machine embodying fea--' tures of the invention; and I .Y Figure 4 is an end elevational view of the machine shown in Figure 3.

Referring more in detail to the drawings:

The pipe straightening machine shown in'Figures 1 and 2 comprises a base It, on which thrust means are carried for bending the pipe to its elastic limit or beyond, as hereinafter explained. The thrust meansinclude-a plurality Qf -10ngitudinally spaced arms I2 upstanding from one edge of said base and afiixed thereto as by welding, and aplurality of bearing blocks l3 upstanding from the mid-portion of said base staggered side elevational .view of an imure 2. The upper edgesof arms [2 preferably are joined by-a horizontal brace 18. The, lower edges of said arms are arcuate. Arcuate bear ing shoes 19 are removably fixed to the lower edges of the arms as by machine screws 20. The arcs of said bearing shoes are substantially quadrants of a circle, the center of which coincides with the axis of shaft JG.

A series of conveyor rolls2] are rotatably car-; ried by 'base [0 betweenbearing blocks 13 and the lower portions of arms l2. A series of vertically movable jackrolls 22 are carried by the base in the longitudinal spaces between conveyor rolls 2| and preferably are hydraulically operated. Pipe lengths P are introduced to' the: straightening machine via conveyor, rolls 2|. They are then elevated via jack rolls 22 to a position where they are contacted by straightening rolls l1.

The face of bearing shoes I9 is radially spaced from the circumference of straightening rolls I! bya distance-sufficiently less than the outside diameter of pipe P that a straight pipe length passing-between the rolls and the bearing shoes;- is bent approximately to its elasticlimitt A; pipe; length that is not straight isthus bent beyond its elastic limit sufiiciently so that its elasticity straightens it as it emerges from the machine; It isseen that the straightening rolls and bean ing shoes apply'lateral thrusts to the pipe, similar to a gag press, although they do not move radially.- The spacing between the straightening rolls and; bearing shoes may be adjusted for different pipe diameters by changing the bearing shoes. Shims areused between the underfaces of the shoes and the faces of the'arms to compensate for roll and shoe wear and to provide for adjustments due "to. pipe diameter variations. The diameter of straightening rolls [1 is at Ieastfour times the outsidediameterof the pipe in order that rotation of the rolls through rotates the pipe through at least one complete revolution.

When jack rolls 22 elevate the pipe into engagement with the straightening rolls, rotation 01. the latter carries the pipe through at least one complete revolution. Since the straightening rolls and bearing shoes contact the pipe and apply lateral thrust forces thereto at spaced apart points and thus bend the pipe to its elastic limit or beyond, such contact through one or more complete revolutions of the pipe effectively removes any bends. As illustrated" Figure 2, several successive pipe lengths'may be straightenened simultaneously, thus further expediting the operation.

After clearing the bearing shoes: andstraightening rolls, the pipe is discharged on a receiving table 23 for further operations 'inits'manufacture.

It is possible also to operate the machine; in That is, pipe may lie-introduced to the reverse. machine at the upper edge ofthesbearing shoes and discharged at the lower end onto conveyor rolls 2|.

In the modified form of pipe straightening machine shown-in Figures?) and 4, both thrust means are rolls, rather thana straightening roll and'a bearing shoe. The machine comprises a base-25, which carries an axially aligned set of bearing blocks-6 and a second axially aligned set'of bearing blocks 21. The two'sets of bearing blocks arev laterally spacedand are in staggered relation. Said bearing blocks each-comprise sets of 'bearings 28' and 29" respectively. A power drivenshaft 30 is rotatably supported in bearings 28. A'shaft 3 I, which may be either power driven in synchronism'with shaft 30 or idling, is rotatably supported in bearings-29i Shafts'30 and 3! carry straightening rolls 32 and 33 respectively between their bearings: The straightening rolls thus are in laterally spaced staggered-relation, the spacing'being sufficient to-bend a straight pipe length approximately to' its elastic limit'as in the first embodiment; The machine may be adjusted for difi'erent pipe diameters by varying the lateral spacing-between bearing'blocks 26 and-2T;

A series of rotatable conveyor-rolls 34 are carriedbythebase between bearing: blocks 26 and ZT'and a-series of jack:rolls-35 arecarried by the base between said conveyor rolls. are introduced to the-machinevia the conveyor rolls and jack rollsas in the first embodiment. One or more upper bearing rolls36 are carried by supports 31 from above and bear on the surface of'pipe.

Jack rolls'35 and upper bearing rol1s36 co operate to retain-the pipe between the straightening'rolls as shown inFigure' l. The pipe is main tained in this'positionthrough'atleast"one revo-- lution; after which-jack rolls-35 are lowered and As in the It' isseen that in-both'embodiments of'theinvention-the pipe is straightenedby bending to its-elastic limit or beyond in a very expeditious fashion. There is no appreciable cold-working ofthe: pipe; except that' incident to straightening the bends. Thus both'embodiments of the ma chine-straighten pipe according to the principle ofithe gagpress and'yetovercome thedisadvanta'ge of slowoperation. Although the machine is described-for straighteningpipe, it'is apparentthe'samemachine could be-used for'straightening Pipe lengths P other elongated cylindrical articles, such as steel bars. Therefore we do not wish to exclude other uses to which the machine may be applied.

The present invention also embraces the novel method of straightening pipe by rotating the pipe through at least one revolution while simultaneously applying lateral thrust forces to oppositesides-z of the pipe, at staggered" points, thus bending the pipe to or beyond its elastic limit.

While we have shown and described only certain embodiments of the invention, it is apparent thatfurthermodifications may arise. Therefore, we do not wish to be limited by the disclosure set fortli' but only" by the scope of the appended 1 claims.

We claim:

1..A straightening machine for elongated cylindricalarticles comprising a base, a plurality of longitudinally spaced arms upstanding from said base, arcuate bearing shoes on said arms adapted to contact-the side walls of articles at longitudinally spaced apart-points in a single line, bearings carriedby said base, a power driven shaft rotatably carried by said bearings, the center of the arcs of said bearing shoes coinciding with the axis of said shaft, and longitudinally spaced straightening rolls carried by said shaft in staggered relation to said bearing, shoes adapted to contact longitudinally spaced'apart points in a single line on the diametrically opposite side of thearticle intermediate the points of contact of said bearing shoes and to rotate the article against said bearing shoes through at least one revolution of the article.

2. A straightening machine for elongated cylindrical articles comprising .a base, a plurality of longitudinally spaced arms'upstanding from said base, arcuate bearing shoes removably fixed on said arms adapted to contact the side. walls of articles at longitudinally spaced apart points in a" single line, bearings carried by said base, a power. driven shaft rotatably carried. by said bearings, the arcs'of said bearing shoes being substantially quadrants of a circle, the center of which coincides with the axis of said shaft, longitudinally spaced straightening rolls carried by said shaft in' staggered relation to said bearing shoes' adapted to contact longitudinally spaced apart points in aisingle line on the diametrically opposite side of the article intermediate the points of contact'of said bearing shoesand to rotate the article against said bearing shoes through at least one revolution of the article, and means on said base for conveying and elevating articles to a position for contact With said bearing shoes and said straightening'rolls.

CARROLL W. MCCLURE. SAMUEL WEBB.

REFERENCES CITED The following references are of record in the file. ofthis patent:

UNITED STATES PATENTS Number Name Date 265,265 Kellogg Oct. 3, 1882 362,287 Krumm May 3, 1887 1,045,161 Machlet Nov. 26, 1912 1,071,945 Moon Sept. 2, 1913 2,335,710 Townsend Nov. 30, 1943 

